GM did make throttle body injection for this engine and renamed it the tech 4. This didn't improve performance much. The iron duke was made for economy and GM took out weight everywhere they could in the name of economy. Because of that, the iron duke crank is very weak, the block is thin, and the rods snap easily at high RPM. Offenhauser made an after market intake manifold and possibly some headers but they are not worth the time or money on this engine. The best two ways to increase performance is to increase air flow and/or increase RPMs. This engine isn't suited well to either. The head flow is very poor and the RPMs can't be increased because of the crank, block, and rod weakness. All is not lost though, as stated many time before, the Mercruiser Marine 180 is a maritime counterpart to the iron duke but is much stronger and more powerful. It does use different components which can be swapped into a duke with machining work. It is easier to swap in a complete mercruiser 180 into your car. There are people on this forum who have done this. Another route is to go to a SD-4 (Pontiac Super Duty 4). The SD-4 is the racing version of the iron duke originally developed for the ARCA racing series. They make a lot of power but parts and/or complete engines are hard to come by and very expensive (I have a 2.5L SD-4 with the 801 head and dual webers and I am probably $10,000 in). Being race engines, they aren't well suited for everyday street use. Guys have been building them and all variations of the iron dukes for performance in the fiero and S10 world for years. FYI, Cosworth Engineering in the UK developed a DOHC head for the SD-4 (which is super rare, the only time I saw one for sale, the kit was $12,000) that can make over 500 hp NA but is peaky.
Topic: Improving General Performance (Read 5510 times)